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Video: Nintendo 3DS: seeing is believing

NEW YORK — U.S. eye specialists are welcoming the Nintendo 3DS game device, dismissing the manufacturer's warnings that its 3-D screen shouldn't be used by children 6 or younger because it may harm their immature vision.

On the contrary, the optometrists say, it's a good idea to get your kids to try the 3-D screen, especially if they're younger than 6. It won't do any harm, they say, and it could help catch vision disorders that have to be caught early to be fixed.

"The 3DS could be a godsend for identifying kids under 6 who need vision therapy," said Michael Duenas, associate director for health sciences and policy for the American Optometric Association.

The new handheld game device is already available in Japan and goes on sale in the U.S. on March 27 for $250. It has two screens like the DS machines it is designed to replace. The top screen can show 3-D images, without the need for special glasses, though only new games will be in 3-D. A pair of cameras on the 3DS can be used to take 3-D pictures.

If your kid doesn't see the 3-D effect on the 3DS, that's a sign that he or she may have a vision disorder such as amblyopia, or "lazy eye," or subtler problems that can cause problems with reading, Duenas said. Kids who experience dizziness or discomfort should also be checked, he said.

Today's 3-D viewing systems send different images to the right and left eyes, a technique that creates an illusion of depth. But a lot of the cues we use to perceive depth in our environment are missing. That confuses the eyes and accounts for the eyestrain and headaches many people experience watching 3-D movies. Because of that, optometrists say, these systems can help isolate problems that have to do with the way the eyes move, problems that aren't caught by eye charts.

These problems are much easier to fix if caught before age 6, when the visual system in our brains is more or less done developing. Only 15 percent of preschool children get a comprehensive eye exam that could catch these subtle problems, according to the American Optometric Association, the professional group for optometrists. More than half of all juvenile delinquents have undiagnosed and untreated vision problems, according to studies.

Going to see a 3-D movie or trying a 3-D TV can also help screen for problems, but optometrists expect the 3DS to be in front of kids' eyes more.

"This has presented my profession, optometry, a wonderful opportunity," said Joe Ellis, the president of the optometrists' association.

However, optometrists aren't quite seeing eye to eye on this issue with another group of eye specialists: the ophthalmologists, who are medical doctors. (Optometrists are doctors of optometry but not medical doctors.)

David Hunter, a pediatric ophthalmologist affiliated with the Children's Hospital in Boston and the American Academy of Ophthalmology, said the idea that off-the-shelf 3-D games or movies could help screen for vision problems such as amblyopia is "a little perplexing."

Kids with amblyopia don't have much depth perception in real life, he said, so if they don't see depth in a 3-D screen, they might not say anything because that wouldn't be much different from what they see around them.

It's not impossible that it could help, but it's "all sort of exploration and speculation," said Hunter, who has started a company that's developing a device for childhood screening of vision disorders.

Nintendo's warning, issued in December, was vaguely worded. It said specialists believe "there is a possibility that 3-D images which send different images to the left and right eye could affect the development of vision in small children."

The Japanese company didn't back the warning up with scientific evidence, so Duenas sees it as being motivated by liability concerns — much like coffee mugs carry warnings that beverages could be hot — rather than a true danger.

Reggie Fils-Aime, the president of Nintendo of America, says the company is "aware of all the work that has been done in the field" and issued the warning based on that work. The warning, he said, is based on research that up until age 6, a child's eye — specifically the connection between the eye and the brain — is still developing.

Nintendo, he said, wants to be "conservative and consistent," erring on the side of safety.

Optometrists haven't seen any sign that 3-D screens can cause lasting damage, but they also acknowledge that not much is known about how 3-D viewing affects us. Hunter, the ophthalmologist, agrees.

The optometrists' association announced this week that it has formed an alliance with the 3DAtHome Consortium, a group of TV manufacturers and Hollywood studios promoting the technology. The idea is that the two groups will share information about the effects of 3-D. In the future, Duenas said, 3-D movies might be preceded by public service announcements recommending vision examinations for those who have problems perceiving the 3-D effect.